Created by ellie on June 10, 2018
Step 1: Place tequila (or cactus juice) and serrano chile in a small cup and let stand one hour. Strain mixture through a fine-mesh sieve over a cup, discard solids.
Step 2: Blend together the remainder of the ingredients (blackberries - salt) iin a blender until smooth. Strain mixture into a pitcher; discard solids. Stir in tequila (cactus juice).
Step 3: Divide mixture among ice-filled glasses. Garnish with additional blackberries and a chile, if desired.